India’s Unique Water Purification Wetland Could Soon Become Extinct

A flock of grey cranes peck for food amidst the shallow
watergrass. Credit: Manipadma Jena/IPS

By Manipadma Jena
KOLKATA, India, Jan 31 2020 (IPS)

Ramkumar Mondal’s farm is awash in a brilliant yellow mustard
bloom. A flock of grey cranes peck for food amidst the shallow
watergrass. But Mondal’s fishpond digs in there like a do-or-die
last sentinel as nearby high-rise buildings, a symbol of
development and encroachment, menacingly tower over the fishpond,
permanently blocking the eastern sun so essential for the pondwater
to convert sewage into fish-feed.

Mondal’s fishpond is part of the East Kolkata Wetlands (EKW),
spread over 12,500 hectares in coastal West Bengal’s Kolkata city
in eastern India that “promotes the world’s largest
wastewater-fed aqua culture system,” Shalini Dhyani, a senior
scientist at India’s Council
of Scientific & Industrial Research (CSIR)-National
Environmental Engineering Research Institute (NEERI)
, told

EKW was designated a Ramsar site in 2002 under
the convention and identified as a perfect example of the
of a wetland ecosystem.

Currently, everyday some one billion litres of wastewater, an
estimated 30 to 50 percent of the sewage from central Kolkata, is
drained into, treated and reused by the fishponds and again drained
out to rice and vegetable farms from where, in about 30 days, the
water drains into the sea.

“Where wastewater might deteriorate the entire wetland water
quality, Kolkata’s wetland cleans its wastewater in just 20
days,” said Dhyani, who is also the South Asia chair Commission
on Ecosystem Management (CEM)
of the International Union for Conservation of
Nature (IUCN)

Where rich biodiversity meets traditional knowledge

A government baseline report prepared on the EKW prior to its
designation as a Ramsar site in 2002 mentions 40 fresh-water and
brackish water fish species were common, 11 of which were
cultivated. Plant species found were 104.

This complex play of diverse organisms from the humble microbes,
wetland plants to more valued fish, aided by sunlight, suitable
temperature, dissolved oxygen in the water – all free of cost –
cleans Kolkata wastewater of 80 percent organic pollution and 99.9
percent coliform bacteria “much better than sewage treatment
plants,” biologists said.

A key insight into how the system works also lies on the
reliance of the fisherfolk feeding the human-waste-turned-to-algae
to their fish.

“In a conventional waste water treatment, booming algae might
be an issue while, in EKW the phytoplankton and algae growth, which
is nothing but optimised human waste, is regularly netted by
fishermen and fed to the fish. Every hectare gets 20 to 60
kilograms of (nature’s free) feed a day,” Dhyani said.

There are also unique bacteria in the wetlands that serve as

“There are 40 species of algae, 2 species of fern, 7 species
of monocot and 21 species of dicots plants plays an important role
in cleaning the sewage water by reducing the eutrophication,
preventing oxygen depletion and ensuring that the fish survive.
Around a dozen aquatic vascular hydrophytes in the region serve as
bio-filters,” said Bonani Kakkar a leading Kolkata-based
environmental activist heading non-profit People United for Better
Living in Calcutta (PUBLIC).

There is no indication of how long the wetlands has been
functioning as a natural waste treatment plant. But it could be
well over a century. The East
Kolkata Wetlands Management Authority’s
(EKWMA) historical
shows that in 1884 underground sewers to the city were
laid, and by this time the waterbodies that now comprises EKW had
already a number of established fish farms.

A conventional Sewage Treatment Plant (STP) would have cost
Kolkata $125 million back in 2010. But thanks to this complex
system in the wetlands, the city has its own free sewage treatment,

according to a University of Essex study

In an area already marked out for ‘development’ Ramkumar
Mondal’s domestic sewage-fed fishpond makes the most of what
little time is left. Harvested rice gives place to a mustard crop
while a pumpkin vine perches over the water. Credit: Manipadma

Aggressive urban encroachment threatens wetland biodiversity,
ecosystem services

One would assume this unique and free natural sewage system
would be highly preserved.

But Kakkar is concerned. It was Kakkar’s non-profit PUBLIC
that in 1991 filed the first-ever lawsuit against land-use change
and encroachment in the EKW that resulted in a major court ruling
the following year.

The 1991 public-interest lawsuit by PUBLIC was
triggered by a veiled land-grab for setting up a World Trade Centre
on 227 acres (90 hectares) of wetland proposed by a private
company, and it was supported by the West Bengal government,” she
told IPS.

Calcutta High Court’s ruled in 1992 and directed the state
government to ensure no change in the wetlands’ land use. 

“The EKW are yet to be demarcated (on the ground, though an
official map exists) 28 years after the court order. A proper
management plan is yet to be formulated,” Kakkar said. 

Because of this lack of management plan and clear demarcation,
there is a frenzy of building activity around the wetlands on land
that was previously designated as “wetlands” but is no longer
legally so and has since been taken over for development.

“From 1992 onward, PUBLIC  has had to file over a dozen
complaints in court against violations of the order, including two
in India’s highest court against projects that received funding
commitment from the state government’s industrial development
wing,” Kakkar said adding, “all of these have posed serious
threats to the biodiversity, flood mitigation and other benefits
offered by the Kolkata wetland.”

High-rise buildings glare down at one small remaining patch of
the East Kolkata Wetlands (EKW) fishponds. Credit: Manipadma

Protection, not development, of the wetlands is needed

“Ironically, some of the biggest threats have been due to the
state government – large construction proposals for a flyover
bridge and another to access the wetlands, for instance,” Kakkar

Studies and anecdotal evidence tell of surreptitious land-use
change where fish ponds are being converted to rice farms aimed
eventually for small industrial or residential utilisation.

EKWMA, the government
custodian, shows on its official website that 391 cases for
violations it has registered with local police from 2007 till 2014.
More recent updates are unavailable. Calls made by IPS to EKWMA for
their response went unanswered.

Rich returns from a perfect nature-based solution

But one thing is clear, between 1980 to 2000 around 2,200
hectares fishponds had been converted to rice paddies.

The remaining 254 individual sewage-fed fish ponds, some single
holdings sprawling over 144 hectares with the smallest being a
third of a hectare, are spread over 3,900 hectares on the eastern
fringes of the city, crisscrossed with canals and creeks, a dead
intertidal river, Bidyadhari, and another named Kulti that carries
the city’s wastewater to the Bay of Bengal.

Together they send 10,000 tonnes of fish to Kolkata’s markets
yearly, fulfilling one-third of the demand in a city of over five
million people.

Not having to buy commercial fish feed saves the farmers

And this “nutrient subsidy” fish growers get from the
wetland and their low transportation cost to their market is passed
on the Kolkata city folks who get fish and vegetable not only farm
fresh but reportedly up to 30 percent cheaper than India’s other
metropolitan cities. For the city’s poor, the wetland fish
remains one of the few affordable protein sources.

Fishing and the vegetable farms in this biodiverse wetland
provides livelihoods, albeit many of these are subsistence-based,
to around 100,000 people including large numbers of women and
children. Maintaining fishponds, catching fish and carrying them
to markets, sowing, weeding and harvesting vegetables and rice are
among several employments, some of which get paid in kind.

“Kolkata’s wetlands ecosystem is an excellent example of a
nature-based solution,” Dhyani told IPS.

Generations of knowledge and practices could be laid to waste by

Dhyani said three generations of EKW fishers’ traditional
knowledge is kept alive from father to sons. Pondwater is cleaned
using kerosene, lime and oil cakes; digging the ponds to the
accurate depth of three to five feet to allow sunlight to the
bottom, mixing the right amount of sewage, maintaining the required
time for conversion of wastewater into fish feed, when to add
spawns and how to protect the embankments from emerging threats of
water hyacinths are knowledge gleaned from long years of

But it is slowly disappearing. Like the wetlands around
Mondal’s fishpond, which has long been converted for development,
though a few straggler ponds remain.

Some of the younger generation have turned away from traditional
wastewater fisheries owing to several factors including an
uncertain future in the face of aggressive urban encroachment and
demand for land for city expansion. 

“My son has completed a diploma in plumbing and left last year
to work in Pune [a city near Mumbai – India’s commercial

“He dreams of going to Saudi Arab, says there is money
there,” he told IPS, with an inaudible catch in his voice.

The post
India’s Unique Water Purification Wetland Could Soon Become
appeared first on Inter Press Service.


World Wetlands Day is on Sunday, Feb. 2. IPS senior
correspondent Manipadma Jena marks the day by visiting the East
Kolkata Wetlands (EKW), a unique wetland that operates as a natural
water purification ecosystem.

The post
India’s Unique Water Purification Wetland Could Soon Become
appeared first on Inter Press Service.

Source: FS – All – Ecology – News
India’s Unique Water Purification Wetland Could Soon Become Extinct